Method of detecting failure of antiparallel thyristor, and power control device

Patent metadata

Field	Value
Publication number	US-12078670-B2
Application number	US-202217949363-A
Country	US
Kind code	B2
Filing date	Sep 21, 2022
Priority date	Sep 28, 2021
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

A method of detecting a failure of an antiparallel thyristor, wherein the antiparallel thyristor includes a first thyristor and a second thyristor connected in parallel and in opposite directions, and is configured to control power supplied from an alternating current power supply to a load, the method including: detecting, as a first detection value, a voltage or a current supplied to the load when ceasing an output command for the second thyristor and issuing an output command for the first thyristor; detecting, as a second detection value, the voltage or the current supplied to the load when ceasing the output command for the first thyristor and issuing the output command for the second thyristor; and determining the failure of the antiparallel thyristor based on a difference between the first detection value and the second detection value.

First claim

What is claimed is:

1. A method of detecting a failure of an antiparallel thyristor, wherein the antiparallel thyristor includes a first thyristor and a second thyristor connected in parallel and in opposite directions, and is configured to control power supplied from an alternating current power supply to a load, the method comprising:
detecting, as a third detection value, the voltage or the current supplied to the load when ceasing the output commands for the first thyristor and the second thyristor to determine whether a short failure occurs in one of the first thyristor and the second thyristor; and
in response to the determination that the short failure has not occurred in at least one selected from the group of the first thyristor and the second thyristor, performing a process including:
detecting, as a first detection value, a voltage or a current supplied to the load when ceasing an output command for the second thyristor and issuing an output command for the first thyristor;
detecting, as a second detection value, the voltage or the current supplied to the load when ceasing the output command for the first thyristor and issuing the output command for the second thyristor; and
determining the failure of the antiparallel thyristor based on the third detection value and based on a difference between the first detection value and the second detection value.

2. The method of claim 1 , wherein the determining the failure of the antiparallel thyristor based on the difference between the first detection value and the second detection value includes determining that, when the difference between the first detection value and the second detection value is equal to or greater than a predetermined first threshold value, the failure has occurred in the antiparallel thyristor.

3. The method of claim 1 , wherein the load is a heater provided inside a member made of an electrically insulating material.

4. The method of claim 2 , wherein the determining the failure of the antiparallel thyristor based on the third detection value includes determining that, when the third detection value is equal to or greater than a predetermined second threshold value, the failure has occurred in the antiparallel thyristor.

5. The method of claim 4 , wherein the load is a heater provided inside a member made of an electrically insulating material.

6. A power control device comprising:
an antiparallel thyristor which includes a first thyristor and a second thyristor connected in parallel and in opposite directions, and is configured to control power supplied from an alternating current power supply to a load; and
a controller configured to control the antiparallel thyristor,
wherein the controller is configured to execute:
detecting, as a third detection value, the voltage or the current supplied to the load when ceasing the output commands for the first thyristor and the second thyristor to determine whether a short failure occurs in one of the first thyristor and the second thyristor; and
in response to the determination that the short failure has not occurred in at least one selected from the group of the first thyristor and the second thyristor, the controller is further configured to execute:
detecting, as a first detection value, a voltage or a current supplied to the load when ceasing an output command for the second thyristor and issuing an output command for the first thyristor;
detecting, as a second detection value, the voltage or the current supplied to the load when ceasing the output command for the first thyristor and issuing the output command for the second thyristor; and
determining the failure of the antiparallel thyristor based on the third detection value and based on a difference between the first detection value and the second detection value.

Assignees

• Tokyo Electron Ltd

Inventors

• Ogino Takashi

Classifications

• H05B1/02

  Automatic switching arrangements specially adapted to apparatus {; Control of heating devices} (thermally-actuated switches H01H37/00) · CPC title

• H05B2203/035

  Electrical circuits used in resistive heating apparatus · CPC title

• H05B1/0202

  Switches · CPC title

• G01R31/3275

  Fault detection or status indication · CPC title

• G01R31/3274

  Details related to measuring, e.g. sensing, displaying or computing; Measuring of variables related to the contact pieces, e.g. wear, position or resistance (measuring contact resistance G01R27/205) · CPC title